Abstracts - Association for Chemoreception Sciences

were phenotyped for detection thresholds for sweet (sucrose),
savory (monosodium glutamate), and salty (NaCl) taste using
age-appropriate psychophysical testings, dietary habits, blood
pressure and obesity. Preliminary analyses revealed that the
detection threshold for sucrose, salt, and MSG are similar to
that previously reported in adults and there were no differences
observed between normal weight children and obese children in
the detection thresholds for any of these basic tastes. In normalweight,
but not obese children, salt detection thresholds were
positively correlated with systolic blood pressure. As a group, the
greater the waist circumference, the lower the sucrose detection
threshold (the more sensitive the child was to sucrose) (p=0.02).
No such relationships existed for salt or MSG in children.
Whether the lower detection thresholds for sucrose are associated
with stronger reinforcing value of sweet foods, as has been
observed in adults, and understanding the link between salt taste
thresholds and blood pressure, are important areas for future
research. Acknowledgements: This project was funded by an
investigator-initiated grant from Ajinomoto, Inc.
#P235 POSTER SESSION V:
HUMAN TASTE PSYCHOPHYSICS;
OLFACTION RECEPTORS; TASTE DEVELOPMENT
Statistical Analysis of Factors Previously Described as
Significant in the Ability to Taste Propylthiouracil Yields
Roles for Age, Sex and Tas2r38 Haplotype, but not
Fungiform Papillae Density
Nicole L. Garneau, Tiffany Derr
Denver Museum of Nature & Science Denver, CO, USA
The Genetics of Taste research study at the Denver Museum
of Nature & Science is in a unique position to collect samples
from a diverse population across a wide age range. Using this
large population sample we set out to establish the scientific
credibility of our community-based laboratory by replicating four
previously reported statistically significant factors in the ability
to taste propylthiouracil; 1)Age, 2)Sex, 3)Tas2r38 haplotype, and
4)Fungiform papillae density. Using regression analysis and the
Student T-test we can replicate the role of age and sex in taste
score (gLMS following a propylthiouracil taste test). Similarly,
the presence of at least one dominant allele for the Tas2r38 gene
is a significant predictor of taste. Finally, in order to decrease
subjectivity, we developed a dichotomous key for objective
analysis of fungiform papillae density. Using this method we did
not find that increased papillae density correlates to an increased
propylthiouracil taste score. In conclusion, the ability to replicate
the significance of age, sex and Tas2r38 haplotype, as well as the
development of objective methodology for papillae analysis, all
demonstrate the ability for citizen-scientists in a communitybased
laboratory to collect, prepare and analyze data that can
contribute to the field of chemoreception. In addition, we submit
that using standardized methodology for fungiform papillae
density allows for a more objective analysis of morphological
data. Using this methodology we find no relationship between
fungiform papillae density and propylthiouracil score in our
data set. This data contradicts previously published studies and
suggests that fungiform papillae density may not be as reliable
a metric for classifying taster status as previously thought.
Acknowledgements: This work was supported by volunteer
citizen-scientists at the Denver Museum of Nature & Science,
and through support from 2008-2012 from R25 RR025066 NIH
NCRR SEPA.
#P236 POSTER SESSION V:
HUMAN TASTE PSYCHOPHYSICS;
OLFACTION RECEPTORS; TASTE DEVELOPMENT
The effects of temperature on sequential and mixture
interactions between sucrose and saccharin
Barry G Green 1,2 , Danielle Nachtigal 1
1
The John B. Pierce Laboratory New Haven, CT, USA,
2
Yale University School of Medicine New Haven, CT, USA
The sweet taste of sucrose and saccharin has been shown to
depend on stimulation of the T1R2-T1R3 receptor, but it is
also clear that these two stimuli interact with the receptor in
different ways. Most recently it was found that self-adaptation is
temperature-dependent for sucrose but not for saccharin (Green
& Nachtigal, 2012), and a previous study showed that high
concentrations of saccharin can block the sweetness of sucrose
(and of itself) and evoke a sweet water taste (Galindo-Cusperino
et al, 2006). The aim of the present study was to determine if
temperature modulates the ability of sucrose to cross-adapt
saccharin and/or of saccharin to block the sweetness of sucrose
and produce a sweet water taste. Subjects rated the sweetness
and bitterness of 0.42 M sucrose, 3.2 mM saccharin, 100 mM
saccharin, or binary mixtures of sucrose and the 2 concentrations
of saccharin, with and without pre-exposure to themselves or
each of the other stimuli. The variables of interest were the
duration of pre-exposure (3 or 10 s) and solution temperature
(37° or 21°C). The stimuli were sampled by dipping the tongue
tip into the solutions, and intensity ratings were made on the
gLMS before the tongue was retracted back into the mouth.
The results confirmed the previous findings and showed that (1)
the magnitude of sweet water taste (after exposure to 100 mM
saccharin) is temperature-dependent, and (2) surprisingly, preexposure
to sucrose for 3 or 10 sec appeared to counteract the
ability of 100 mM saccharin to block sweetness, independent of
temperature. These results support the hypothesis that sucrose
and saccharin bind to at least 2 different sites on the T1R2-T1R3
receptor and raise new questions about the factors that can
affect excitatory and inhibitory interactions between these sites.
Acknowledgements: Supported in part by NIH grant DC005002
POSTER PRESENTATIONS
Abstracts are printed as submitted by the author(s).
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